Harry Roussard:
My Sierra has only TWO flap settings, 15 degrees and 35 degrees; there is not a 25-degree setting at all, from what I can see. The handbook states that there are THREE flap settings (plus Flaps UP of course), but my mechanic tells me the mechanism ONLY ALLOWS for TWO settings. Anybody have any ideas around this??
Editor:
Most likely, your Sierra has either been improperly repaired, or was mis-assembled at the factory. There was a Mandatory Service Bulletin, later FAA-mandated by AD 78-04-01, that required replacement of the Flap Weld Assembly. I wonder whether there is any chance that someone installed an incorrect ratchet assembly at the time that AD was complied with. Even though the AD did not address that specific part, it had to be R&R’d during the AD compliance.
The flap control ratchet assembly (PN 169-524043-3 or -7) determines how many “notches” of flaps you will have. All the flaps are supposed to have a maximum extension of 35 degrees, plus or minus one degree, per the A1CE Type Certificate. The -3 ratchet has two notches, and the -7 ratchet has three notches. The -3 ratchet only applies to airframes M0001 through M0554 (no other models or SNs). The Placard that goes on the flap handle, showing the extension positions, also shows only the two notches for these serial numbers.
If there are other, later airframes that also have only the two notches of flaps, I would suspect we have found yet another example of a mismatch between the Beech parts books, and their actual assembly practices on the line when the planes were built.